This invention relates to a process of preparing a rare earth catalyst useful in an alkoxylation process.
A large variety of products useful, for instance, as nonionic surfactants, wetting and emulsifying agents, solvent, and chemical intermediates, are prepared by the addition reaction (alkoxylation reaction) of alkylene oxides (epoxides) with organic compounds having one or more active hydrogen atoms. For example, particular mention may be made of the alkanol ethoxylates and alkyl-substituted phenol ethoxylates prepared by the reaction of ethylene oxide with aliphatic alcohols or substituted phenols of about 6 to 30 carbon atoms. Such ethoxylates, and to a lesser extent corresponding propoxylates and compounds containing mixed oxyethylene and oxypropylene groups, are widely employed as nonionic detergent components of commercial cleaning formulations for use in industry and in the home. As another example, the addition reaction of propylene oxide with polyols provides intermediates for the preparation of polyurethane products.
An illustration of the preparation of an alkanol ethoxylate (represented by formula III below) by addition of a number (n) of ethylene oxide molecules (formula 11) to a single alkanol molecule (formula I) is presented by the equation: 
The present invention particularly relates to an alkoxylation reaction catalyzed by the phosphate salts of one or more of the rare earth elements.
Alkylene oxide addition reactions are known to produce a product mixture of various alkoxylate molecules having different numbers of alkylene oxide adducts (oxyalkylene adducts), e.g., having different values for the adduct number n in formula III above. The adduct number is a factor which in many respects controls the properties of the alkoxylate molecule, and efforts are made to tailor the average adduct number of a product and/or the distribution of adduct numbers within a product to the product""s intended service.
It is known that alcohol alkoxylate products having a narrow range alkylene oxide adduct distribution are preferred for use in certain detergent formulations (Great Britain Patent No. 1,462,134; Derwent Publications Research Disclosure number 194,010). Narrow-range alcohol alkoxylates are also known to be particularly valuable as chemical intermediates in the synthesis of certain carboxylated alkyl polyethers (U.S. Pat. No. 4,098,818) and of certain alkyl ether sulfates (Great Britain Patent No. 1,553,561).
U.S. Pat. No. 5,057,627 describes an alkoxylation process catalyzed phosphate salts of the rare earth elements. These catalysts were typically prepared by adding an aqueous solution of a rare earth compound such as lanthanum chloride to an aqueous sodium orthophosphate or H3PO4 solution. The resulting catalyst was a solid powder that was stable with a long shelf-life. However, often the reaction mixture prepared by these catalysts lead to an increase in the viscosity of the mixture to 1000 centipoise or more. U.S. Pat. No. 5,057,627 also describes a process where an alkylphosphate is added to a lanthanum solution of 2-ethoxyethanol and NEODOL(trademark) 23 Alcohol. Such a system may produce a lower viscosity mixture, however, these catalysts have a slow reaction time.
It is desirable to prepare a catalyst that provides a low viscosity reaction system with faster reaction time.
A process for the preparation of a fluid rare earth phosphate catalyst composition comprising:
a) providing a rare earth salt soluble in C9-C30 active hydrogen containing organic compounds at a temperature of less than 120xc2x0 C.;
b) adding and dissolving the rare earth salt in a C9-C30 active hydrogen containing organic compounds thereby producing a rare earth/organic solution; and
c) adding phosphoric acid to the rare earth/organic solution in a rare earth to phosphoric acid molar ratio in the range of 0.7:1 to 1.3:1 thereby producing the fluid rare earth phosphate catalyst composition.
Further, processes for the preparation of alkylene oxide adducts of active hydrogen containing organic compounds are provided, comprising contacting an alkylene oxide reactant comprising one or more vicinal alkylene oxide with an active hydrogen containing reactant comprising one or more active hydrogen containing organic compounds in the presence of the fluid catalyst composition prepared by certain processes.